RIOK1 and breast cancer: The finding that RIOK1 was up-regulated at the protein level in PCa cells extends the number of cancer types with proved RIOK1 overexpression.10, 11, 12,14,15 In a study by Huang et al13 in breast cancer, proliferation was inhibited and apoptosis was induced with knockdown of RIOK1, consistent with the present results in PCa after RIOK1 inhibition.